What is meant by a homologous series?

A homologous series is a family of organic compounds that share the same functional group and the same general formula, in which each member differs from the one before it by a CH₂ unit.

Define the term functional group.

A functional group is the atom or group of atoms in a molecule that is responsible for the characteristic chemical reactions of that molecule.

Why do all the members of one homologous series undergo the same kinds of reaction?

They all carry the same functional group, and it is the functional group rather than the carbon chain that decides how a molecule reacts.

Give the general formula of an alkene containing one carbon–carbon double bond.

Such an alkene has the general formula CₙH₂ₙ.

CCEA AS-Level Chemistry 1110

Formulae, Equations and Amounts of Substance

Topic overview Ionic charges and the formulae of compound ions Writing and balancing full and ionic equations The mole, molar mass and Avogadro's constant Reacting masses and reactants in excess Hydrated salts and water of crystallisation

Atomic Structure

Topic overview Protons, neutrons and electrons Atomic number, mass number and the composition of ions Isotopes and relative isotopic mass Relative atomic, molecular and formula mass Mass spectra and relative atomic mass calculations Mass spectra of diatomic elements Electronic configuration and the building up principle Orbitals, electron spin and orbital shapes The s-, p-, d- and f-blocks of the Periodic Table Ionisation energies and their equations Trends in ionisation energy as evidence for shells and subshells

Bonding

Topic overview Ionic bonding and electron transfer Dot and cross diagrams for ionic compounds Covalent bonding and the shared pair Lone pairs and co-ordinate bonding Dot and cross diagrams for covalent molecules and ions The octet rule and its limitations Electronegativity and bond polarity Metallic bonding

Intermolecular Forces and Structure

Topic overview Van der Waals' forces and permanent dipole-dipole attractions Hydrogen bonding, boiling points and solubility Giant ionic, metallic and giant covalent structures Molecular covalent structures and melting points across Period 3

Shapes of Molecules and Ions

Topic overview Electron pair repulsion and VSEPR theory Shapes and bond angles up to four electron pairs Shapes with five and six electron pairs Polar bonds and polar molecules

Redox

Topic overview Rules for assigning oxidation states Oxidation states in peroxides, hydrides and Roman numeral names Oxidation, reduction and electron transfer Oxidising agents, reducing agents and disproportionation Half-equations and combining them into redox equations

The Halogens

Topic overview Colours, physical states and solubility of the halogens Chlorine with water and the treatment of drinking water Disproportionation of the halogens with sodium hydroxide Oxidising ability and displacement reactions Solid halides with concentrated sulfuric and phosphoric acid

Acid-Base Titrations

Topic overview Strong and weak acids and bases Concentration, molarity and units Preparing a standard solution Titration technique, mean titres and uncertainty Indicators and the end point Titration calculations

Qualitative Tests

Topic overview Chemical tests for the gases Flame tests for metal cations Testing for the ammonium ion, sulfate and carbonate Distinguishing the halides, and the starch test for iodine

Formulae and Amounts of a Substance

Topic overview Empirical and molecular formulae Calculating formulae from composition data Molar gas volume and reacting gas volumes Percentage yield Atom economy

Nomenclature and Isomerism in Organic Chemistry

Topic overview Homologous series and functional groups IUPAC rules for naming organic compounds Structural, displayed and skeletal formulae Structural isomerism Geometrical isomerism and E–Z notation

Alkanes

Topic overview Alkanes as saturated hydrocarbons Boiling points of alkanes and van der Waals' forces Boiling points of branched isomers Complete and incomplete combustion of alkanes Pollutants from alkane fuels and the atmosphere Catalytic converters Radicals, homolytic fission and heterolytic fission Free radical substitution of alkanes

Alkenes

Topic overview Unsaturated hydrocarbons and the bromine water test Sigma and pi bonds in the carbon–carbon double bond Electron density at C=C, reactivity and catalytic hydrogenation Addition of chlorine and bromine to alkenes Addition of hydrogen chloride and hydrogen bromide Electrophiles, heterolytic fission and the addition mechanism Carbocation stability and Markovnikov addition Addition polymerisation of alkenes

Halogenoalkanes

Topic overview Classification and boiling points of halogenoalkanes Laboratory preparation of a halogenoalkane from an alcohol Nucleophiles and hydrolysis with aqueous alkali Reactions with ammonia and with potassium cyanide Relative rates of hydrolysis and carbon–halogen bond enthalpy Elimination using ethanolic potassium hydroxide CFCs and the ozone layer

Alcohols

Topic overview Hydrogen bonding, boiling point and solubility of alcohols Classifying alcohols and preparing them from halogenoalkanes Combustion of alcohols and their use as fuels Reactions with sodium, hydrogen bromide and phosphorus pentachloride Oxidation with acidified potassium dichromate(VI)

Infrared Spectroscopy

Topic overview Molecular vibrations and the absorption of infrared radiation Characteristic absorptions and the wavenumber scale Identifying functional groups from infrared spectra Distinguishing compounds and following reactions by infrared

Energetics

Topic overview Exothermic and endothermic changes Standard conditions and the standard enthalpy change Enthalpy level diagrams Standard enthalpies of combustion and formation Standard enthalpy of neutralisation Measuring enthalpy changes by experiment Enthalpy calculations using q = mcΔT Hess's Law and enthalpy cycles Indirect enthalpy calculations using Hess's Law Average bond enthalpies and their limitations

Kinetics

Topic overview Reaction rate and the factors that change it Collision theory and activation energy The Maxwell–Boltzmann distribution of molecular energies Catalysts and the activation energy barrier

Equilibrium

Topic overview Reversible reactions and dynamic equilibrium Changing conditions and the position of equilibrium The equilibrium constant Kc and its units The magnitude of Kc and the extent of reaction Industrial processes and compromise conditions

Group II Elements and Their Compounds

Topic overview s-block character and electronic configuration Trends in atomic radius and first ionisation energy Reactions of the elements with oxygen, water and dilute acids The oxides and their reactions with water and dilute acids Thermal stability of the carbonates and hydroxides Uses of magnesium oxide, calcium carbonate and lime Solubility trends and solubility curves

Nomenclature and Isomerism in Organic Chemistry

5 subtopics
14 things to know
Unit AS 2

What Nomenclature and Isomerism in Organic Chemistry covers

Nomenclature and Isomerism in Organic Chemistry is examined in Unit AS 2, Further Physical and Inorganic Chemistry and an Introduction to Organic Chemistry, and drawn on again in Unit AS 3, Basic Practical Chemistry. It covers homologous series and functional groups, IUPAC rules for naming organic compounds, structural, displayed and skeletal formulae, structural isomerism and geometrical isomerism and E–Z notation.

Where it is assessed

Unit AS 2

Further Physical and Inorganic Chemistry and an Introduction to Organic Chemistry, and again in Unit AS 3, Basic Practical Chemistry.

Check the CCEA specification ↗

The 5 subtopics

Each one has its own page. CCEA AS Chemistry students sit this topic in the first year.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Give the general formulae of the alkanes, of an alkene with one double bond, and of the alcohols.

Key term

What does the label E mean in the name of an alkene?

Key term

How is the stem of an IUPAC name chosen?

Key term

What does a displayed formula show?

Key term

Define the term structural isomerism.

Key term

Why do the physical properties of a homologous series change gradually as the series is ascended?

Key term

How are two or more identical substituent groups shown in a name?

Key term

Describe what a skeletal formula shows.

Key term

Name the three types of structural isomerism.

Key term

Why is there no geometrical isomerism about a carbon–carbon single bond?

Key term

Give the general formula of the alkanes.

Key term

Write the structural formula of butane.

Key term

What is chain isomerism?

Key term

How is the priority of the two groups on a doubly bonded carbon atom decided?

Take Nomenclature and Isomerism in Organic Chemistry further

The same content, four other ways.

Questions from this topic

Each one with the model answer underneath.

1
What is meant by a homologous series?
Model answer
A homologous series is a family of organic compounds that share the same functional group and the same general formula, in which each member differs from the one before it by a CH₂ unit.
2
Define the term functional group.
Model answer
A functional group is the atom or group of atoms in a molecule that is responsible for the characteristic chemical reactions of that molecule.
3
Why do all the members of one homologous series undergo the same kinds of reaction?
Model answer
They all carry the same functional group, and it is the functional group rather than the carbon chain that decides how a molecule reacts.
4
Why do the physical properties of a homologous series change gradually as the series is ascended?
Model answer
Each member has one more CH₂ unit than the last, so the relative molecular mass and the strength of the van der Waals' forces rise in regular steps.
5
Give the general formula of the alkanes.
Model answer
The alkanes have the general formula CₙH₂ₙ₊₂.
6
Give the general formula of an alkene containing one carbon–carbon double bond.
Model answer
Such an alkene has the general formula CₙH₂ₙ.

See the rest and revise

What is inside Levo

Six ways to work the same material.

1Closed book

2Open book

3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Formulae, Equations and Amounts of Substance

Atomic Structure

Bonding

Intermolecular Forces and Structure

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

Yellow to .

brownbluegreen

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AThe reactants total 159.6 + 84.0 = 243.6.

BThe two moles of iron have a mass of 111.6.

CThe atom economy is 45.8%.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

There are 1000 cm³ in one dm³.

TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Nomenclature and Isomerism in Organic Chemistry revision questions

Is Nomenclature and Isomerism in Organic Chemistry examined at AS in CCEA Chemistry?: Yes. It sits in Unit AS 2, which you take in the first year, so it is on the AS paper as well as counting towards the full A level.
What does Nomenclature and Isomerism in Organic Chemistry cover in CCEA AS-Level Chemistry?: 5 subtopics: homologous series and functional groups, iupac rules for naming organic compounds, structural, displayed and skeletal formulae, structural isomerism and geometrical isomerism and e–z notation. Each one has its own page with questions and model answers.
How is Nomenclature and Isomerism in Organic Chemistry organised?: By the CCEA 1110 specification, subtopic by subtopic, so it matches the order you are taught it in.

Every question in Nomenclature and Isomerism in Organic Chemistry, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Start revising, £5 a month See how the method works

Or £46 a year, about £3.83 a month. Cancel anytime.